I've got my block preped and the crank and pistons are in. After I put my cam in, I run #1 piston to the top of the block, then when I install my timing chain and sprockets, do both timing marks need to be at 12 o'clock or cam at 6 o'clock and crank at 12 o'clock?

 

install the crank and cam gear dot to dot, makes it easier to see and line up. then spin the engine a few time (by hand) and make sure they stay lined up (don't ask how i know this). after you're sure the two marks are lined up spin it again with both dots straight up and the #1 piston at TDC. this is the firing position for #1 and then you point the rotot to the #1 position on the cap and it should be close enough to fire when you crank it. when it fires set the timing. i like to have a light already hooked up and awrench for the distributor ready.

 

Yes. The cam gear dot is supposed to be at 6 o'clock or 12 o'clock.

It's easier to see what you're doing and get it accurate if the cam gear dot is at 6 o'clock.

However, that cam position is #6 firing, i.e. it's the other instance of #1 TDC besides the one that's #1 firing. So, if you put it together with the cam dot at 6 and then spin the crank one rev, the cam gear dot will then be at 12 o'clock and you'll be at #1 firing.

 

since the cam spins at half the speed of the crank, it doesnt matter.


however dot to dot is easier to see because they're closer together....

 

Thanks for the info.